All of a sudden, instead of dealing with urban sprawl and water rights, you're tasked with using a bunch of poorly controlled, dim-bulb A.I. legionnaires to defend against invading hordes. Battles have nothing to do with tactics, being determined only by who has the bigger, better-equipped force.

Online or offline, as a campaign or a freeform scenario, Caesar IV is an inviting game, easy to like and hard to stop playing. It's got a fairly forgiving learning curve, and it will rarely plunge you into the sort of economic death spirals that can make other city builders so discouraging.